I feel it as soon as I stand up..and yep tingling and numbing pretty much everywhere, but mostly my lower legs & knees

I got diagnosed with orthostatic hypotension months ago but have had it for years before and experience these symptoms as well. one thing my doctor has recommended was to increase salt intake to help rise blood pressure

Maybe I have a better doctor... i was given a great list of things to do and after a year of not being able to do much due to symptoms, I hardly notice them! I've had to work very very hard at it, but my fainting and dizziness hardly bothers me now. Just adding salt to food is useless. I started buying liquid IV, the drink powder, in bulk. I drink it everyday through out the day. Treat mental illness. Take medication if needed. Increase cardio exersice. Symptoms (light headed ness/fuzzy brain) start to increase after 5 days of not exersicing. Get sleep! Please sleep. Set timer, take melatonin, get a prescription if needed. Track your symptoms. Keep a notebook with you for 2 weeks. Notice exactly what is triggering your dizziness. How long were you sitting? Were you standing for a long time? Was it hot? Did you take a nap. Then you can start to pin point what not to do. If you can prevent the black outs, headaches, and leg tingles eventually when they do happen, it won't be so bad. It's like living life on a healthy balance beam. You should be super healthy anyway. It just stinks when you lose your balance for a few days.